Final answer:
The estimated ecosystem respiration (Re) for the stream is Carbon Dioxide Release (c).
Step-by-step explanation:
Ecosystem respiration (Re) refers to the release of carbon dioxide by organisms in an ecosystem through respiration. It is the process by which organisms break down organic compounds to release energy, and carbon dioxide is one of the byproducts. Therefore, the estimated ecosystem respiration for the stream would be Carbon Dioxide Release (c).